The present invention relates to medical methods of treatment. More particularly, this invention concerns methods of treating non-small cell lung cancer, head and neck cancers, and breast cancers in mammals, including man, employing 5-methyl-6-[[(3,4,5-trimethoxyphenyl)amino]methyl]-2,4-quinazolinediamine or a pharmaceutically acceptable salt thereof alone or in combination with other antineoplastic agents.
Antifolate drugs have been used in cancer chemotherapy for over thirty years. N-[4-[[(2,4-diamino-6-pteridinyl)methyl methylamino]benzoyl]-L-glutamic acid, also commonly known as methotrexate, is an antifolate drug which has been used in the treatment of gestational choriocarcinoma and in the treatment of patients with chorioadenoma destruens and hydatiform mole. It is also useful in the treatment of advanced stages of malignant lymphoma, and in the treatment of advanced cases of mycosis fungoides.
However, many patients with cancers of the head and neck, choriocarcinoma, certain forms of lung cancer, and others, do not respond to methotrexate, and patients who do respond initially often relapse. Also, many patients with other forms of cancer such as common gastrointestinal malignancies, rarely respond to methotrexate chemotherapy.
Research efforts have therefore focused on the discovery of new antifolate compounds which have a broader spectrum of antineoplastic activity, which overcome the common mechanism of methotrexate resistance, and which have a more acceptable toxicity profile.